Adhesive applicator tips with improved flow properties

ABSTRACT

An article of manufacture for dispensing an adhesive material, such as a synthetic or semi-synthetic polymerizable or cross-linkable monomer material, includes a container body, and a porous applicator tip having a proximal end that is attached to the container body, and a distal end located away from the container body, wherein the adhesive material is located in the container body in a non-contacting relationship with the applicator tip prior to dispensing the material. A flow pattern of the adhesive material within or on the applicator tip is controlled by providing one or more cuts in the applicator tip to alter flow properties of the adhesive material through the applicator tip.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/479,059, filed Jan. 7, 2000, the entiredisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to an improved design for an applicatortip, particularly for use with an applicator that dispenses adhesivematerial. In particular, the present invention relates to an applicatortip that exhibits an improved flow pattern of the adhesive material inor through the applicator tip, which allows for more precise placementof the adhesive material and decreased waste of adhesive material.

[0004] 2. Description of Related Art

[0005] Monomer and polymer adhesives are used in both industrial(including household) and medical applications. Included among theseadhesives are the 1,1-disubstituted ethylene monomers and polymers, suchas the α-cyanoacrylates. Since the discovery of the adhesive propertiesof such monomers and polymers, they have found wide use due to the speedwith which they cure, the strength of the resulting bond formed, andtheir relative ease of use. These characteristics have made theα-cyanoacrylate adhesives the primary choice for numerous applicationssuch as bonding plastics, rubbers, glass, metals, wood, and, morerecently, biological tissues.

[0006] It is known that monomeric forms of α-cyanoacrylates areextremely reactive, polymerizing rapidly in the presence of even minuteamounts of an initiator, including moisture present in the air or onmoist surfaces such as animal (including human) tissue. Monomers ofα-cyanoacrylates are anionically polymerizable or free radicalpolymerizable, or polymerizable by zwitterions or ion pairs to formpolymers. Once polymerization has been initiated, the cure rate can bevery rapid.

[0007] Medical applications of adhesive compositions include use as analternate or an adjunct to surgical sutures and staples in wound closureas well as for covering and protecting surface wounds such aslacerations, abrasions, burns, ulcers such as stomatitis, sores, andother open surface wounds. When an adhesive is applied to surfaces to bejoined, it is usually applied in its monomeric form, and the resultantpolymerization gives rise to the desired adhesive bond.

[0008] However, with the application of adhesive in its monomeric form,due to the rapid polymerization rate of the monomers, it has beenchallenging to design effective and commercially viable packaging anddispensing systems. Such packaging and dispensing systems mustcounterbalance the competing requirements that the monomer notprematurely polymerize, that the monomer be easily applied, that themonomer polymerize at a desired rate upon application, and that thesanitary and/or sterile properties of the monomer and applicator—whetherreal or perceived—be maintained.

[0009] In order to meet the above requirements, various dispensing andpackaging systems for adhesives have been proposed. These systemsinclude large bottles with a single applicator, such as a large single-or multi- use brush; small applicators such as small ampoules containingmonomer, for example within an internal frangible vial, that can beexpelled through an integral or replaceable applicator; and the like.However, a problem with many of these applicator systems is that theproduct contains more adhesive material than is necessary for aparticular use. Because of the rapid polymerization rate of themonomers, any unused adhesive is generally discarded, because either theremaining monomer undergoes polymerization, or the monomer polymerizeswithin the applicator to render the applicator unusable.

[0010] A disadvantage of some known applicator systems, and particularlyapplicators containing a frangible vial and a porous applicator tip forexpelling the adhesive, is that monomer material may be wasted byfilling the pores of the applicator tip in areas other than the areasused to apply the adhesive. Furthermore, some known applicator tipssuffer from the problem of the monomer being expelled through the entiresurface area of the tip, and even to greater extents in areas other thanthe area used to apply the monomer to the desired substrate. Forexample, large amounts of adhesive become expelled from areas around theperiphery of the applicator tip, where the applicator tip meets theapplicator housing, rather than through the end of the applicator tip,as is often desired. This leads to a further problem of less precisecontrol over the area of application of the monomer to the substrate.

[0011] For example, an effective applicator system is disclosed in U.S.Pat. No. 5,928,611 to Leung. This patent discloses an applicator systemgenerally comprising a tube containing a frangible vial of monomericadhesive composition. One end of the tube is sealed, and the other endis closed by an applicator tip comprising a solid support having apolymerization or cross-linking accelerator or initiator for themonomeric adhesive disposed thereon or therein. As shown in FIG. 3 ofthe patent, the applicator tip can be generally dome shaped. Anapplicator device of U.S. Pat. No. 5,928,611 is shown as FIG. 1 herein.The applicator device 100 comprises a cylindrical applicator container200 holding polymerizable and/or cross-linkable material 300 enclosed ina frangible vial 400, and an applicator tip 500 containing apolymerization and/or cross-linking initiator.

[0012] However, a difficulty encountered with such a dome-shapedapplicator tip, as well as with other solid applicator tips, is that themonomeric adhesive material being expelled through the applicator tiptends to follow paths of least resistance within the tip. That is, asthe monomeric adhesive is being expelled, it tends to follow theshortest paths through the tip, which tend to be around the periphery ofthe tip, rather than following the longer path through the full lengthof the tip to the end of the tip. Because the end of the tip is desiredto be used to apply the adhesive, less precise control of placement ofthe adhesive is obtained because adhesive becomes expelled through theentire surface of the tip. This also tends to result in waste ofadhesive material, because all of the adhesive does not exit from thetip at the same location.

[0013] Applicator devices commercially used for Loctite Product No.11067-2 and Permatex Product No. ATA-1 contain crushable glass ampouleswithin flexible applicators. However, the compositions within thecrushable ampoules are, in both products, adhesive activators, not theadhesive composition itself In both of these products, the adhesive iscontained in a separate dispenser. The dispenser system used for theseproducts is physically similar to that shown in FIG. 1, except that theapplicator tip is rectangular in shape, rather than dome-shaped, and theapplicator tip does not contain a polymerization and/or cross-linkinginitiator for an adhesive material contained in the frangible vial. Inthis product also, the above-described problems of wasted material(here, initiator) and less precision in application are also present.

[0014] Accordingly, a need exists in the art for improved applicator tipdesigns, which will allow more precise placement of the adhesivematerial. A need also exists in the art for a means to decrease waste ofmonomeric adhesive material, by ensuring that the adhesive materialeither exits at the desired location of the applicator tip, or flows tosuch a desired location on the tip.

SUMMARY OF THE INVENTION

[0015] The present invention addresses the above needs by providingapplicator tips that possess increased precision in control of placementof the adhesive composition, and a decrease in waste of adhesive. Theapplicator tips of the present invention provide either more uniform orpreferentially controlled paths of resistance within the applicator tip,or provide means for channeling adhesive to an application zone and awayfrom other surface areas of the applicator tip.

[0016] A benefit provided by the present invention is thus the abilityto apply adhesive material in precise patterns, such as in thin lines.The present invention also allows tailoring of the application patternbased on alternative designs of the applicator tip, thus allowingflexibility in application of, for example, from thin lines to thickerlines. The present invention also decreases waste of adhesive material,by allowing effective use of a greater portion of the volume of adhesivematerial contained within the applicator. In embodiments, it alsoimproves the utilization of polymerization and/or cross-linkinginitiator and/or rate modifiers present in the tip.

[0017] The present invention provides an article of manufacture fordispensing adhesive material, comprising a container body, and a porousapplicator tip having a proximal end that is inserted into or attachedto the container body, and a distal end located away from the containerbody, wherein the adhesive material is located in the container body ina non-contacting relationship with the applicator tip prior todispensing the adhesive material.

[0018] According to embodiments of the present invention, the applicatortip may be sectioned, such as by cutting. The sectioning can be formedas, for example, cuts through an entire portion (length, width and/ordepth) of the applicator tip, or through only a portion thereof. Thesectioning can also be in the form of channels formed through the bulkmaterial of the applicator tip. This sectioning provides for increasedflow control for application of the material.

[0019] In embodiments of the present invention, the applicator tip maybe configured such that a flow path length ratio A/B is less than 1.5,wherein B represents a length of a shortest flow path of adhesivematerial through the material of the applicator tip to an externalsurface of the applicator tip adjacent the container body, and Arepresents a length of a shortest flow path of the adhesive materialthrough the material of the applicator tip to an external surface of apredetermined application subportion such as the distal end of theapplicator tip. In embodiments, the applicator tip can comprise one ormore grooves that channel adhesive exiting the applicator tip fromperipheral portions of the applicator tip to the distal end of theapplicator tip. In embodiments, the applicator can comprise a protectivecover surrounding at least a part but not all of an area of theapplicator tip extending out of the container body. In embodiments, theapplicator tip can be a hollow porous applicator tip having a proximalend that is inserted into or attached to the container body, and adistal end located away from the container body.

[0020] In other embodiments of the present invention, the applicator tipcan be formed to include both a first portion that is non-porous orsubstantially non-porous, and a second portion that is porous. In thisembodiment, the flow paths of the adhesive material through theapplicator tip is altered because the adhesive material will flow onlythrough the porous section of the applicator tip.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a side clevational view of an applicator deviceaccording to the prior art.

[0022]FIG. 2 is a cross-sectional view of an applicator tip according tothe prior art.

[0023]FIGS. 3a-3 d are cross-sectional views of applicator tipsaccording to the present invention.

[0024]FIG. 4 is an elevational view of an applicator tip according tothe present invention.

[0025]FIGS. 5a-5 d are elevational views of applicator tips according tothe present invention.

[0026]FIGS. 6a-6 d are elevational views of applicator tips according tothe present invention.

[0027]FIGS. 7a-7 c are elevational views of a luer lock connection forattaching an applicator tip to an applicator body.

[0028]FIG. 8 is an elevational view of an assembled applicator deviceusing the luer lock system of FIGS. 7a-7 c.

[0029]FIG. 9 is a cross-sectional view of a sectioned applicator tipaccording to the present invention.

[0030]FIGS. 10a-10 d are cross-sectional views of sectioned applicatortips according to the present invention.

[0031]FIGS. 11a-11 b are top-down views of sectioned applicator tipsaccording to the present invention.

[0032]FIG. 12 is a top-down view of a sectioned applicator tip accordingto the present invention.

[0033]FIGS. 13a-13 b are top-down views of sectioned applicator tipsaccording to the present invention where the sectioning is formed as oneor more channels.

[0034]FIGS. 14a-14 b are top-down views of applicator tips according tothe present invention that include both a porous and a non-poroussection.

[0035]FIGS. 15a-15 c are elevational views of applicator tips accordingto the present invention that include both a porous and a non-poroussection.

DETAILED DESCRIPTION OF EMBODIMENTS

[0036] The present invention provides improved applicator tips andapplicator devices that provide significant improvement in theapplication and use of adhesive material. Such applicator tips can beused, for example, in combination with the adhesive compositions andpackaging and dispensing systems set forth in U.S. Pat. No. 5,928,611,the entire disclosure of which is incorporated herein by reference. Ofcourse, other adhesive compositions, compatible with the applicators ofthe present invention, can also be used.

[0037] In embodiments of the present invention, an improved applicatortip is provided wherein the shape and/or construction of the applicatortip is selected so as to control the flow pattern of the adhesivethrough and/or on the applicator tip. For example, the shape of theapplicator tip can be selected so as to control the flow paths of theadhesive material, or the surface of the applicator tip can beconfigured to channel adhesive material exiting the applicator tip to apredetermined location, preferably the location used to apply theadhesive.

[0038] For example, in the prior art, the lengths of the flow paths ofthe adhesive are generally longer from the inside of the applicator tothe end of the tip than they are from the inside of the applicator tothe periphery or edge surfaces of the applicator tip adjacent the end ofthe container body. This is shown, for example, in FIG. 2. FIG. 2 is anenlarged scale, cross-sectional view of the prior art applicator tip500. FIG. 2 shows simplified schematics of the flow paths of adhesivematerial through the applicator tip 500 to areas outside of thecontainer body 200. In FIG. 2, the flow paths 501,501′ through theapplicator tip to the end of the tip are longer than, for example, theflow paths 502,502′ to the periphery or external surface of theapplicator tip. In the prior art applicator tip, the flow path length501 is about 11 mm, and the flow path length 502 is about 7 mm, giving aratio of 1.57. Thus, because the flow paths 502,502′ are shorter thanthe flow paths 501,501′, more of the adhesive composition tends tofollow these paths.

[0039] One means for controlling and improving flow properties accordingto the present invention is to select the overall shape of theapplicator tip. Accordingly, in an embodiment of the present invention,the shape of the applicator tip is selected to provide flow paths ofmore uniform length, or even of reversed proportions, from the inside ofthe applicator to the periphery of the applicator tip. Examples of suchapplicator tips according to the present invention are shown incross-section in FIGS. 3a-3 d.

[0040]FIG. 3a is a cross-sectional view of an applicator tip 10according to the present invention. FIG. 3a shows simplified schematicsof the flow paths of adhesive material through the applicator tip 10 toareas outside of the container body 19. In FIG. 3a, the lengths of theflow paths 11,11′ through the material of the applicator tip to anexternal surface of the end of the tip are more closely equal to, forexample, those of the flow paths 12,12′ through the material of theapplicator tip to an external surface of the applicator tip adjacent thecontainer body. That is, as compared to the corresponding flow paths inthe applicator tip of FIG. 2, the flow paths to the end of the tip areshorter in FIG. 3a than in FIG. 2. Thus, because the lengths of the flowpaths 11,11′ are more equal to those of the flow paths 12,12′, there ismore uniform flow of the adhesive through the applicator tip, and theadhesive composition tends to flow or express more uniformly through theapplicator tip.

[0041] In embodiments of the present invention, the applicator tip 10can assume different shapes, as desired. For example, the end of theapplicator tip located nearest the frangible vial, i.e., located withinthe applicator body 19, can have different shapes as shown innon-limiting fashion in FIGS. 3a-3 d. For example, the end of theapplicator tip can be curved or otherwise designed to equilibrate theflow path lengths. As shown in FIG. 3b, the lengths of the flow paths11,11′ through the material of the applicator tip to an external surfaceof the end of the tip are substantially equal to, for example, those ofthe flow paths 12,12′ to an external surface of the applicator tipadjacent the container body. This thus provides a more uniformexpression of the adhesive material through the entire surface of theapplicator tip.

[0042] Reversed flow profiles, such as where more adhesive flows throughthe distal end of the applicator tip than through peripheral or sideportions of the applicator tip, can also be provided. For example, inthe applicator tip shown in FIG. 3d, the flow paths through the materialof the applicator tip at the distal end are shorter than flow paths tothe remaining surface of the applicator tip.

[0043] Alternatively, or in addition, the end of the applicator tip canbe shaped so as to accommodate the frangible vial. In these embodiments,the curvature or shape of the end of the applicator tip located nearestthe frangible vial can be designed to more closely match the shape ofthe frangible vial. However, it is preferred that a tight fit betweenthe frangible vial and the internal surface of the applicator tip is notmade, so that there is sufficient room for adhesive material to exit thefrangible vial and enter and pass through the applicator tip. That is,for example, it is preferred that the frangible vial does not enter thetip, which can be accomplished, for example, by providing a frangiblevial that has a diameter greater than the internal diameter of thecurved portion of the applicator tip.

[0044] In embodiments of the present invention, it is preferred that thewalls of the applicator tip are of substantially uniform thickness asshown in FIG. 3b. Because the flow pattern of the adhesive through theapplicator tip is related to the length of the flow path through theapplicator tip, providing substantially equal flow distances helps toprovide equal flow throughout the applicator tip. Of course, theapplicator tip walls can be made thinner in desired areas, such astoward the end of the applicator tip, if desired. This would tend toincrease flow of the adhesive through the thinner portions.

[0045] Still further, in embodiments of the present invention, the endof the applicator tip located furthest from the frangible vial, i.e.,located outside of the applicator, can have different shapes as shown,for example, in FIGS. 3a and 3 c. For example, the end of the applicatortip can have a smooth curvature, as in FIG. 3a, for application of theadhesive material. Alternatively, or in addition, the end of theapplicator tip can be configured so as to provide, for example, moreprecise application of the adhesive material. For example, as in FIG.3c, the applicator tip can have an extension portion thereon, whichdraws the adhesive material to a more defined application area. Thisextension can have any shape and dimension and can, for example, betubular, conical, rounded, or the like.

[0046] Likewise, the overall shape of the applicator tip can be any ofvarious shapes. For example, suitable shapes of the applicator tip areshown in FIGS. 3a-3 d as being a dome-shape. However, the presentinvention is not limited to such shapes. Rather, any suitable size andshape applicator tip can be used. Generally, the dimensionalcharacteristics are limited only by the intended use of the applicator,and practicality considerations. Suitable shapes include, but are notlimited to, conical, cylindrical, chisel or polygonal shapes.Furthermore, the desired shapes can be either solid (i.e., having asubstantially flat (or planar) bottom end, as shown in FIG. 2), curved(i.e., having a curved bottom end, as shown in FIG. 3a), or hollow(i.e., having a substantially hollow bottom end, as shown in FIGS. 3band 3 c). Of course, other geometries can be used, as desired. Thelength and size of the tip can be varied depending on variousapplication parameters. The tip may be detachable from the applicatorbody, or may be an integral part of the applicator.

[0047] In the case of using chisel tips, and even other shaped tips, thedistal end of the applicator tip can come to a sharp point (such as achisel shape being formed by two intersecting planar portions).Alternatively, the distal end of the applicator tip can be rounded over,or can have a flattened shape, such as by not having the planesintersect at the distal end. Still further, as shown in FIG. 5d, theapplicator tip can have other configurations, such as being formedsimilar to a marker tip to permit more comfortable and natural use ofthe applicator.

[0048] Because it is desired in embodiments of the present invention tocontrol and equalize adhesive flow through the applicator tip, it ispreferred in embodiments that the proximal end of the applicator tip,i.e., the end nearest the frangible vial or adhesive material, be shapedso as to help achieve such controlled flow. Thus, for example, theproximal end of the applicator tip may be curved, cut-out or hollowed toat least some extent. As used herein, “hollow” is meant to refer to ashape of the applicator tip where a distinct lumen is present in theapplicator tip, as opposed to a porous tip where numerous pores defineopen space within the applicator tip. Thus a porous tip may or may notalso be hollow.

[0049] In embodiments, the shape of the applicator tip can be formed byany suitable means or manufacturing process. For example, the hollowshaped applicator tips can be formed by molding the applicator tipmaterial into the desired hollow or other shape, or a solid material canbe shaped and/or hollowed, for example, by drilling, filing, boring,cutting, gauging, or the like.

[0050] In these embodiments of the present invention, the shape of theapplicator tip is selected so as to control the length of the adhesivematerial flow paths within the applicator tip. By so controlling thelengths of the flow paths, the distribution of adhesive exiting theapplicator tip can be made more uniform, or can establish a specificdesired distribution. Thus, for example, whereas the flow rate ofadhesive in the prior art may have been higher at the periphery or sidesurfaces of the applicator tip than at the distal end of the applicatortip, the applicator tips of the present invention can provide a moreuniform, preferably substantially uniform, flow pattern or expressionthroughout the exposed surface of the applicator tip. In otherembodiments, the shape can be selected such that the flow path lengthwithin the applicator tip is less in the direction to the end or anotherdesired portion of the applicator tip than it is to other areas of theapplicator tip, for example the peripheral or side areas. That is, inthese embodiments, a higher distribution of adhesive is expressed in theapplication area than in the periphery or side portions of theapplicator tip. Such distribution helps to prevent waste of adhesivematerial, and provides for improved precision of application of theadhesive.

[0051] According to embodiments of the present invention, a more uniformprofile of adhesive expression is provided in the applicator tip. Thiscan be obtained, for example, by providing an applicator tip wherein thelengths of the shortest flow paths of the adhesive through the materialof the applicator tip are substantially equal over the exposed portionof the applicator tip. For example, the lengths of the flow paths can beapproximated and measured by measuring a shortest distance of travel ofadhesive through the material of the applicator tip to an outer surfaceof the applicator tip.

[0052] Thus, for example with reference to FIGS. 3a and 3 b, theshortest flow paths to an external surface of the applicator tipadjacent the applicator body are represented by lines 12,12′. Likewise,the shortest flow paths to the distal end of the applicator tip arerepresented by lines 11,11′. In measuring the lengths of the flow paths,the distance within the open or hollowed-out area of the applicator tipis not included in the length of the flow path, because this distance isopen space that does not impede adhesive flow. If the length of theshortest flow path through the material of the applicator tip to anexternal surface of the applicator tip adjacent the applicator body isdenoted B, and the length of the shortest flow path through the materialof the applicator tip to an external surface of the distal end of theapplicator tip is denoted A, then the value A/B can be used to representa flow path length ratio. In embodiments of the present invention, it ispreferred that the flow path length ratio be less than 1.5, preferablyless than 1.3, more preferably about 1 or less than 1. In embodiments,this ratio is preferably about 1, indicating that the flow paths in theapplicator tip are substantially uniform, and that there are nosignificantly shorter flow paths. In other embodiments, this ratio canbe adjusted so as to be less than 1, such as less than or equal to about0.9, 0.8 or 0.5 or less, indicating that the monomeric adhesive materialencounters shorter flow paths through the material of the applicator tipto the point of application of the adhesive, such as the distal end ofthe applicator tip, than to other areas of the applicator tip.

[0053] A further benefit of embodiments of the present invention is thatthe total pore volume of the applicator tip can be decreased. As aresult, less of the adhesive material gets trapped in the pores of theapplicator tip, resulting in less waste of material.

[0054] In embodiments of the present invention, an alternative oradditional approach to controlling and improving flow properties is toalter the surface of the applicator tip, for example to channel adhesivematerial exiting the applicator tip to a common location, preferably thelocation used to apply the adhesive. One means to accomplish thisobjective is to form channels in the surface of the applicator tip.These channels will cause adhesive material exiting the applicator tipto flow on the surface of the tip to the desired area of application.Thus, for example, where a dome-shaped or cone-shaped or chisel-shapedapplicator tip or the like is used, channels can be formed in thesurface of the tip to channel adhesive material exiting on the peripheryto travel towards the end of the applicator tip.

[0055]FIG. 4 shown an exemplary applicator tip according to thisembodiment of the invention. As shown in FIG. 4, the applicator tip 20has formed in the surface thereof multiple channels or grooves, shown asv-shaped grooves 21, which converge toward the end of the applicatortip. Of course, such grooves need not be v-shaped, but can assume anydesired shape so long as the function of channeling adhesive material tothe application area is achieved. For example, the grooves or channelscan be v-shaped, u-shaped, square, semi-circular, semi-oval, or thelike. In addition, the grooves or channels can be formed such that theyare exposed on the surface, or they can be formed to be located beneaththe surface of the applicator tip.

[0056] Furthermore, in this embodiment of the present invention, theapplicator tip need not be dome-shaped, as shown in FIG. 4. Rather, anysuitable applicator tip shape can be utilized. For example, aparticularly suitable applicator tip shape is a chisel-shape. As shownin FIGS. 5a-5 b, the applicator tip can be shaped, for example, as agenerally dome shape with two opposing substantially planar faces formedto define a chisel tip at the end of the applicator tip. That is, thechisel tip is formed by two intersecting planes in the applicator tip.

[0057] When such a chisel shape is used for the applicator tip, theintersecting planes forming the tip can be formed at any desired angle,based for example on the desired use of the applicator. For example, theangle of intersection forming the chisel tip can, in embodiments, beanywhere from 5 to 170°. Preferably, the angle of intersection isbetween about 20 and about 90°, more preferably between about 40 andabout 70°. Of course, values outside of these ranges can be used, inembodiments, as desired.

[0058] The tip 30 can also have formed in the surface thereof multiplechannels or grooves, as described above and shown as v-shaped grooves31, which converge at the chisel tip end of the applicator tip. Ofcourse, such grooves need not be v-shaped, but can assume any desiredshape as described above so long as the function of channeling adhesivematerial to the application area is achieved. FIGS. 5a-5 c also show acentral interior portion of the applicator tip 30 hollowed out, as shownby dashed lines 32. As described above, such design is optional, and canbe present or not, as desired. Thus, as shown in FIG. 5d, the centralportion can be solid.

[0059] As also shown in FIGS. 5a-5 b, the grooves formed in the surfaceof the applicator tip can be parallel to each other, or can be offset ata desired angle. For example, as shown in FIG. 5a, the grooves 31 can begenerally parallel to each other, so that adhesive material travellingthrough the bulk applicator tip is channeled to the chisel end of theapplicator tip. However, as shown in FIG. 5b, the grooves can be offset(i.e., non-parallel) by a desired amount. This may be desirable, forexample, where it is known that a larger amount of adhesive materialpasses through the central portion of the applicator tip as compared tothe outer portions of the applicator tip. By making the grooves 31non-parallel, the adhesive material flowing through the central portionof the applicator tip can be dispersed along the width of the chiseltip. This aids in providing a more uniform coating of adhesive materialon the desired surface.

[0060] In embodiments of the present invention where the grooves aremade nonparallel on the face of the applicator tip, it is suitable tooffset the grooves at any desired angle. For example, adjacent lines canbe offset at an angle of, for example, from about 1 to about 15°.Preferably, the adjacent grooves are offset at an angle of from about 2to about 10°, more preferably from about 3 to about 7°.

[0061] Furthermore, this embodiment of the present invention is notlimited to the chisel shape shown in FIGS. 5a-5 b. Rather, any suitableshape can be used to achieve particular results in use of theapplicator. For example, where chisel shapes are used, the shape, width,and slope of the chisel shape can be adjusted to provide differentresults. For example, a wide chisel tip can be provided where a widearea of application is desired, while a narrow chisel tip can beprovided where a thin or narrow area of application is desired.Alternatively, the tip can be provided in other shapes, such as conicalshapes, pyramidal shapes, and the like, where the end of the applicationtip either comes to a point, is rounded over, or is flattened.

[0062] Although FIGS. 5a, 5 b and 5 d show the applicator tip ascontaining only three grooves on the visible face of the applicator tip,the invention is not so limited. Rather, one or more grooves can beformed on each face of the applicator tip. Such grooves can be eitherseparated by a planar (or curved) surface, as in FIGS. 5a, 5 b and 5 d,or the grooves can be located continuous and adjacent to each other, asshown in FIG. 5c. Furthermore, although the grooves are shown as beingplaced only on the planar faces of the chisel-shaped tip, the presentinvention is not limited to such embodiments. Rather, if desired, thegrooves can additionally, or alternatively, be placed on non-planarportions of the applicator tip. Such placement could further channel theexiting adhesive composition to the desired point of application.

[0063] In these embodiments of the present invention, the shape of theapplicator tip and the number and placement of grooves on the surface ofthe applicator tip are also selected so as to alter the effectivedistribution of adhesive material on the surface of the applicator tip.By providing grooves on the surface of the applicator tip, the effectsof gravity, surface tension and capillary action act to draw the exitingadhesive material from the non-application areas of the application tipto the application area of the applicator tip. Thus, for example,whereas the adhesive distribution on the surface of the applicator tipin the prior art may have been higher at the periphery of the applicatortip, the applicator tips of the present invention can provide a higherquantity of adhesive material at the application area, and lesserquantities of material on the remaining surface of the applicator tip.Accordingly, the travel of the adhesive material is effectivelychanneled or “focused” to the application area. Such channeling helps toprevent waste of adhesive material, and provides for improved precisionof application of the adhesive material.

[0064] In embodiments of the present invention, the flow pattern ofadhesive material from the applicator tip can be altered by blockingflow from desired portions of the applicator tip. Thus, for example, ifit is desired that adhesive material exits only through the end of theapplicator tip, and not through peripheral portions, such flow patterncan be accomplished by altering the design of the applicator tip toblock flow through such undesired areas. This can be accomplished, forexample, by altering the physical structure of surface areas of theapplicator tip, such as by filling the pores of such areas with amaterial that will prevent flow through those areas, or by covering theareas with a separate material to prevent flow.

[0065] As used herein, the term “cover” is used to refer to any suitablemeans for preventing adhesive material from exiting through desiredportions of the applicator tip. Thus, as will be described below, a“cover” includes physically separate components that are placed on orattached to the applicator tip to block adhesive flow, can be a coatingor layer applied to the surface of the applicator tip to block adhesiveflow, or can be the result of a method of altering at least the surfacelayer of the applicator tip so as to likewise block adhesive flow.

[0066] For example, FIGS. 6a-6 d show exemplary embodiments of thepresent invention where the flow pattern is adjusted by blocking theexit of adhesive material from desired areas of the applicator tip. InFIG. 6a and FIG. 6b, the applicator tips 40,50 are shown as beingtreated in portions to prevent adhesive from exiting the applicator tipin the treated areas. FIG. 6a represents a hollow dome-shaped applicatortip, whereas FIG. 6b represents a chisel-shaped applicator tip havinggrooves 54 formed in the flat surfaces thereof. In each of theseembodiments, the areas 45,55 (shown in the Figures using stipling) ofthe applicator tip are treated or coated so as to block exit of theadhesive material, such that the material does not exit to the surfaceof the applicator tip. In these embodiments, the adhesive material willthus be forced to proceed through the applicator tip and exit only inthe desired areas.

[0067] In these embodiments, any suitable treatment or coating materialmay be used to treat or coat the otherwise exposed surfaces of theapplicator tip to prevent adhesive material from exiting in those areas.For example, the applicator tip can be coated by a cured form of theadhesive material, other cured or curable polymeric materials, materialsthat provide barrier properties upon setting, or the like. Likewise, anysuitable material may be coated upon the desired surface of theapplicator tip, which provides the desired blocking characteristics tothe applicator tip. For example, suitable solid, semi-solid, or liquidparticles can be directly applied to the applicator tip surface, or canbe dispersed in a suitable coating material (such as a solvent,dispersant or the like) and coated onto the applicator tip. For example,acceptable results can be obtained by dissolving polymeric materials,such as butyrate, in a suitable solvent, such as acetone, and coatingthe resultant solution onto the desired portions of the applicator tip.As a further example of the above, suitable materials such as paints,sealants, or the like can be applied onto the desired portions of theapplicator tip to provide the adhesive blocking property.

[0068] Alternatively or in addition, the treatment can include anysuitable method that alters the properties of the surface of theapplicator tip. For example, heating, melt smearing, ultrasonic welding,spray coating or the like can be used at the desired portions of the tipso as to close the pores in that area. Likewise, a suitable material canbe applied to the applicator tip to close the pores. For example,applying a suitable solvent, such as acetone or the like, can close thepores of the applicator tip. Preferably, such treatment affects only thesurface of the applicator tip, or only to a small depth of theapplicator tip, so as not to plug the applicator tip or otherwise renderit inoperable.

[0069] In alternative embodiments, shown in FIGS. 6c and 6 d, theapplicator tips 40,50 are shown as being covered in portions by aseparate component that prevents adhesive from exiting the applicatortip in the covered areas. FIG. 6c represents a hollow dome-shapedapplicator tip, whereas FIG. 6d represents a chisel-shaped applicatortip having grooves 54 formed in the flat surfaces thereof. In each ofthese embodiments, areas of the applicator tip are covered with aseparate component or cover 46,56 to block exit of the adhesivematerial, such that any adhesive material that exits to the surface ofthe applicator tip is not exposed to the environment. In theseembodiments, the bulk of the adhesive material will thus be forced toproceed through the applicator tip and exit only in the desired areas.

[0070] In these embodiments, the cover 46,56 is a separate component,which can be applied to the applicator tip as part of the manufacturingprocess, or can be applied to the applicator tip by the user prior touse. The cover 46,56 can be attached to the applicator tip by anysuitable means.

[0071] As used herein, the terms “attach” or “attached” as referring tothe applicator tip means operably connecting the applicator tip to theapplicator body, or parts thereof, directly or through other components.Thus, for example, the applicator tip can be attached to the applicatorbody in any suitable way, including but not limited to mechanicalarrangements such as luer locks, threads or locking rings, pressureand/or friction fitting, adhesive or chemical arrangements such asadhesive or chemical bonding, heat-shrink attachment, ultrasonicwelding, and the like.

[0072] For example, the cover can be adherently bonded to the applicatortip, can be attached to the applicator tip by heat-shrinking the coveronto the applicator tip, can be screwed onto the applicator tip bysuitable threads or locking rings (not shown) or can be held to theapplicator tip by pressure and/or friction. Adherent or heat-shrinkattachment may be preferred in embodiments where the cover is not to beinterchangeable, or where the cover is attached during the manufacturingprocess. However, screw, locking or friction/pressure attachment may bepreferred in embodiments where interchangeability is desired, such aswhere different sizes or types of covers are available. Suchinterchangeable tips can be used, for example, to provide differentdegrees of coverage of the applicator tip or to alter the profile ofapplication of the adhesive material.

[0073] In these embodiments, any suitable material may be used to formthe cover, which in turn covers the otherwise exposed surfaces of theapplicator tip to prevent adhesive material from exiting in those areas.For example, the covers can be made from natural materials such ascellulose, cardboard, metal, ceramic, plastics such as butyrate or highdensity polyethylene, polypropylene, polyester, or the like.Alternatively, the cover can be formed from the tip material itself,such as from the surface layer of the tip material, such as by theabove-described processes.

[0074] In FIGS. 6a-6 d, the applicator tip is shown as having a hollowcentral interior portion of the applicator tip 40,50, as shown by dashedlines 42,52. As described above, however, such design is optional, andcan be present or not, as desired.

[0075] In embodiments of the present invention, the applicator tipmaterial can be either porous or solid. By porous materials are meantthose through which the adhesive material can flow through, such as bypassing through pores of the material. By non-porous or solid materialsare meant those through which the adhesive material cannot flow, eitherbecause there are no pores, or because the pores are so small that thematerial is effectively non-porous. Travel of the adhesive materialthrough the solid materials would thus be by way of the sectionings madeaccording to the present invention.

[0076] In other embodiments of the present invention, the applicator tipcan be formed using a combination of materials that are porous, such asdescribed above, and non-porous, or substantially non-porous withrespect to the material to be applied using the applicator tip. Forexample, the applicator tip in embodiments may be formed with one ormore sections of non-porous or substantially non-porous material, andone or more sections of porous material. In such embodiments, thenon-porous (or substantially non-porous) section generally prevents flowof material through the section, while the porous section permits flowthrough the section. In this manner, the flow of material through theapplicator tip can be controlled. Such control can, for example, provideprecise flow control to enable placement of the material exiting theapplicator tip in a fine line and/or at precise locations.

[0077] For example, FIGS. 14a and 14 b show top-down views of applicatortips. The applicator tips each include a non-porous section 92 thatsurrounds a porous section 94. As shown and as will be apparent, theplacement of the porous section or sections within the non-poroussection or sections can be symmetrical, as in FIG. 14a, ornonsymmetrical, as in FIG. 14b. FIGS. 15a and 15 b show elevationalviews of the applicator tips shown in FIGS. 14a and 14 b, respectively.

[0078] Preferably, in these embodiments, the porous section(s) and thenon-porous sections(s) are coextensive in a fluid-flow direction throughthe applicator tip. That is, for example, it is preferred that theporous section(s) extend entirely through the applicator tip, to permitexpression of the desired material through the applicator tip. However,if desired, the non-porous section(s) can be altered to alter the fluidflow through the applicator tip, such as by providing a small exposurewithin the applicator tip, but increasing through the applicator tip toa small porous section. This is shown, for example, in FIG. 15c, wherethe porous member 94 starts out with a larger area, to permit easyuptake of material, but narrows to a smaller area to permit preciseplacement of the material. The non-porous section 92 likewise starts ata small area, but enlarges consistent with the narrowing of the poroussection 94.

[0079] In these embodiments, any suitable non-porous material can beused, such that the material is non-porous, or substantially non-porouswith respect to the material to be applied using the applicator tip.Suitable non-porous materials include, but are in no way limited to,polyethylenes such as low density polyethylene and high densitypolyethylene, as well as other non-porous materials.

[0080] According to the present invention, the applicator can beattached to a suitable applicator body, such as a tube, in any suitableway. For example, the applicator tip can be attached to an end of theapplicator body by annealing, bonding or form-fitting the applicator tipinto or onto an opening in the applicator body. In embodiments of thepresent invention, the applicator tip can be attached to the applicatorbody using a luer lock configuration. Luer lock configurations provide abenefit of being able to change the applicator system, such as changingthe design of the applicator tip, without the resulting need to redesignthe entire product configuration. That is, by providing a Luer lockmechanism on the applicator body, any of various applicator tips cansubsequently be applied to the applicator body.

[0081] According to this aspect of the present invention, the luer lockconnector can also provide the desired effect of channeling the adhesivematerial toward a desired external surface application subportion of theapplicator tip, such as the distal end of the applicator tip. This canbe accomplished because a portion of the applicator tip can be hollowedout to accept the luer lock connector. Thus, as the adhesive materialflows through the luer lock connector, it flows through further towardthe application subportion before actually entering the material of theapplicator tip. Accordingly, the luer lock can provide the double effectof providing a means of attaching the applicator tip to the applicatorbody, and providing shorter flow path lengths of the adhesive throughthe material of the applicator tip.

[0082] When used, the luer lock connection can be made in any desiredconfiguration. Suitable constructions of the luer lock mechanism areshown in non-limiting fashion in FIGS. 7a-c. FIG. 7a shows an exemplaryapplicator body 20 having attached to one end a cap 60 having a maleluer lock connector 62. The cap 60 can be made of any suitable material,such as the same materials that are used to form the applicator body 20.A corresponding female luer lock connector 64 is supported in a tipretainer and support member 63, as shown in FIG. 7b. The tip retainerand support member or platform 63 can be formed in any configuration asdesired, but are depicted as having an open area into which theapplicator tip can be placed. Such a platform could be formed, forexample, by injection molding the platform around an applicator tip, byforming the applicator tip around a preformed platform, or by attachinga preformed applicator tip to a preformed platform. Preferably, as shownin FIG. 7b, the applicator tip 70 includes a hollow area or void 72,suitable for receiving the female luer lock connector 64 when the tipretainer and support member 63 is mated with the applicator tip. Oncemated, the components form a unitary component, as shown in FIG. 7c.

[0083] The applicator tip bearing the luer lock connector can then beattached to the applicator body bearing a corresponding luer lockconnector, to form a complete applicator device, as shown in FIG. 8. Ofcourse, although this embodiment has been described herein as theapplicator body having a male luer lock connector and the applicator tipas having a female luer lock connector, the invention is not so limited.Rather, these connectors can be reversed, as desired.

[0084] Although all of the above-described embodiments provide improvedflow properties and improved flow control for applying the material fromthe applicator, still further improvements can be made. In particular,according to the present invention, the flow properties and flow controlcan be further improved by providing an applicator tip that issectioned. As used herein, the term “sectioned” refers to the applicatortip as having been cut one or more times to provide an apparentplurality of sections in the applicator tip. Such cuts can be completelythrough the applicator tip, resulting in several distinct parts, or thecuts can be only partially through the bulk portion of the applicatortip, such that the applicator tip remains as a unitary part. Preferably,for ease of handling and manufacture, the cuts are not made completelythrough the bulk material.

[0085] An example of a sectioned applicator tip according to the presentinvention is shown as an enlarged scale, cross-sectional view in FIG. 9.FIG. 9 shows the applicator tip 80 as being inserted into a containerbody 82. The applicator tip 80 is sliced or sectioned by one or morecuts, shown in FIG. 9 as cuts (dashed lines) 84. Although FIG. 9 showsthe cuts as extending to slightly below the end of the container body,the depth of the cuts can be any depth that may be desired. As shown inFIGS. 10a-10 d, the cuts can extend only slightly into the applicatortip and not into the area defined by the container body (FIG. 10a); thecuts can extend down to about the point where the container body ends(FIG. 10b); or the cuts can extend through the applicator tip into thearea defined by the container body, to any distance up to the end of theapplicator tip (FIG. 10c). Furthermore, multiple cuts in the sameapplicator tip can extend different distances, as desired. For example,FIG. 10d shows cuts in the central portion as extending further thancuts in an outer portion of the applicator tip.

[0086] In embodiments of the present invention, the location of the cutsor sectionings can be in any desired form. For example, in FIG. 9, thesection cuts are depicted as being parallel to each other. However, thesectioning cuts need not be parallel, and can instead be non-parallel oreven intersecting. For example, FIGS. 11a-11 b depict top-down views ofthe applicator tip using alternative sectioning cuts. FIG. 11a showsthree section cuts, made generally according to that shown in FIG. 9.FIG. 11b shows four section cuts, made to substantially intersect at thedistal end of the tip. Of course, numerous other configurations of thesectioning cuts can be made, depending on the desired flowcharacteristics of the material to be applied.

[0087] In embodiments of the present invention, the cuts or sectioningscan extend through an entire width, depth and/or length of theapplicator tip material, or they can extend only a portion of suchdimension. For example, FIGS. 11a and 11 b show the cuts as extendingacross a full width or length of the applicator tip material. However,as shown in FIG. 12, the cuts can extend across only a portion of thedimension. For example, FIG. 12 shows the cuts or sectionings 84 as notfully reaching the outer circumference of the applicator tip 80.

[0088] In embodiments, the sectioning can be made by forming channels orpassageways, rather than in the form of discrete cuts. For example, thesectioning can be in the form of one or more channels cuts through theapplicator tip material. This construction of the sectioning isparticularly suitable for applicator tips made from materials that arenon-porous, or substantially non-porous with respect to the material tobe applied using the applicator tip. For example, FIGS. 13a and 13 bdepict applicator tips where the sectioning is formed as one or morechannels 85 formed in the applicator tip material 80. The channels canbe formed in any suitable size or shape as desired to accommodateapplication of the material.

[0089] Furthermore, although the sectioning has been shown with respectto a solid, dome-shaped cylindrical applicator tip, the invention is notlimited to such embodiments. Rather, the sectioning of the presentinvention can be applied to any or all of the various applicator tipdesigns described above, including those that have hollowed out innerareas, surface grooves, covers, or the like, those that are of differentshapes such as chisels, and those that have extension portions at thedistal end of the applicator tip.

[0090] When the section cuts are to be used, the cuts may be made by anyconventional means including by a knife, saw, drill, borer, or the like.Alternatively, the cuts can be made by initially forming them in thematerial during the tip manufacturing process, such as by molding or thelike.

[0091] Preferably, the number and location of the section cuts aresufficient to alter the flow properties of the material through theapplicator tip. According to embodiments of the present invention, thenumber of cuts can be from as low as 1 to as many as will effectively beaccommodated by the applicator tip. The number of cuts can thus range,for example, from 1, 2, 3, 4 or 5 or more, to 5, 10 or 15 or more, orany value in between.

[0092] According to the present invention, the applicator can includeany suitable adhesive material. The adhesive material can includemonomeric (including prepolymeric) materials, polymeric materials, ormixtures thereof. The monomer (including prepolymeric) adhesivecomposition may include one or more polymerizable monomers. Preferredadhesive compositions for use in applicators of the present inventionare useful as tissue adhesives, sealants for preventing bleeding or forcovering open wounds, and in other biomedical applications. They finduses in, for example, apposing surgically incised or traumaticallylacerated tissues; retarding blood flow from wounds; dressing burns;dressing skin or other superficial or surface wounds such as compromisedskin or other tissue (such as abrasions, chaffed or raw skin, minor cutsand scrapes, sores and/or ulcers such as stomatitis); protecting intactskin; and aiding repair and regrowth of living tissue. Adhesivecompositions of the present invention are also useful in industrial andhome applications, for example in bonding rubbers, plastics, wood,composites, fabrics, and other natural and synthetic materials.

[0093] Preferred monomers that may be used in this invention are readilypolymerizable, e.g. anionically polymerizable or free radicalpolymerizable, or polymerizable by zwitterions or ion pairs to formpolymers. Such monomers include those that form polymers, that may, butdo not need to, biodegrade. Such monomers are disclosed in, for example,U.S. Pat. No. 5,328,687 to Leung, et al., which is hereby incorporatedin its entirety by reference herein.

[0094] Particularly preferred adhesive materials are 1,1 -disubstitutedethylene monomers including, but not limited to, monomers of theformula:

HRC═CXY  (I)

[0095] wherein X and Y are each strong electron withdrawing groups, andR is H, —CH═CH₂ or, provided that X and Y are both cyano groups, a C₁-C₄alkyl group. Examples of monomers within the scope of formula (1)include α-cyanoacrylates, such as ethyl, butyl, and/or 2-octylcyanoacrylate, vinylidene cyanides, C₁-C₄ alkyl homologues of vinylidenecyanides, dialkyl methylene malonates, acylacrylonitriles, vinylsulfinates and vinyl sulfonates of the formula CH₂═CX′Y′ wherein X′ is—SO₂R′ or —SO₃R′ and Y′ is —CN, —COOR′, —COCH₃, —SO₂R′ or —SO₃R′, and R′is H or hydrocarbyl.

[0096] Furthermore, the adhesive composition contained in the applicatorcan further include various additives as are known in the art, includingbut not limited to flavorants, preservatives, plasticizing agents,stabilizing agents, formaldehyde concentration reducing agents, pHmodifiers, thickening agents, cross-linking agents, fibrousreinforcement agents, colorants, and the like.

[0097] Suitable compositions, methods of making such compositions, andmethods for incorporating such compositions into a dispenser device aredescribed, for example, in U.S. Pat. Nos. 5,928,611 to Leung; 5,328,687,5,514,371, 5,514,372, 5,575,997, 5,582,834 and 5,624,669, all to Leunget al; 5,259,835 to Clark et al.; 3,527,841 to Wicker et al.; 3,722,599to Robertson et al.; 3,995,641 to Kronenthal et al.; and 3,940,362 toOverhults; and U.S. patent application Ser. Nos. 08/266,647, 08/714,288,09/099,457, 09/430,177, and (100497.02 filed Oct. 29, 1999), the entiredisclosures of which are incorporated herein by reference.

[0098] According to the present invention, the applicator tip may, butneed not, include a polymerization and/or cross-linking initiator and/orrate modifier, such as an accelerator or inhibitor, for a polymerizablemonomer adhesive material contained in the applicator. Suitablepolymerization and/or cross-linking initiators and rate modifiers, andmethods for applying them to the applicator tip, are described in, forexample, U.S. Pat. No. 5,928,611 and U.S. patent application Ser. No.09/430,177, filed Oct. 29, 1999, Ser. Nos. 09/430,176, 09/430,289,09/430,290, and 09/430,180 filed Oct. 29, 1999; Ser. No. 09/343,914filed Jun. 30, 1999; Ser. No. 09/385,030 filed Aug. 30, 1999; and Ser.No. 09/176,889 filed Oct. 22, 1998, the entire disclosures of which areincorporated herein by reference. Preferred initiators for some medicaluses include benzalkonium chloride, and for some industrial uses includedimethyl toluidine.

[0099] In embodiments of the present invention where a polymerizationand/or crosslinking initiator and/or rate modifier, or other material,is included in the applicator tip, the material can be included in theapplicator tip in any suitable or desirable manner. For example, thematerial may be loaded in the tip, such that it is loaded in pores orinterstices of the applicator tip material, and/or the material may bechemically or physically attached to the applicator tip material,whether on exterior or interior surfaces thereof. In embodiments, thematerial can also be loaded in the applicator tip in proximity to thesectionings or cuts. For example, the material may be chemically orphysically attached to the applicator tip material on exposed surfacesaround the sectionings or cuts, such as being chemically or physicallyattached to the exposed surfaces of channels formed in the applicatortip. This latter approach is particularly suitable for solid applicatortips, where pores do not exist, or where pores do exist but aresubstantially inaccessible by the adhesive material to be applied.

[0100] The polymerization and/or cross-linking initiator and/or ratemodifier may be applied to the applicator tip by any suitable means,including, but not limited to, spraying, dipping, injecting, or brushingthe applicator tip with a liquid medium containing the polymerizationand/or cross-linking material. It is preferably applied to the tip bydipping or injecting. For example, it may be applied to the tip bypumping of the liquid medium, for example, through a syringe, onto thedistal end of the applicator tip.

[0101] The polymerization and/or cross-linking initiator and/or ratemodifier may be applied to porous applicator tips by using a vacuum orpressure process. In each process, a solution or suspension of thepolymerization and/or cross-linking initiator and/or rate modifier isintroduced into a vacuum or pressure chamber. The applicator tips,either individually or preferably in batches, are placed into thesolution or suspension in the pressure vessel in a manner such that theapplicator tips preferably do not float to the top of the solution orsuspension. For example, the applicator tips can be placed in thesolution or suspension in a wire basket or other suitable container,which would hold the applicator tips under the solution or suspension,or a wire mesh or other suitable retainer could be placed over theapplicator tips to dunk or sink them into the solution or suspension.Once the applicator tips are in the solution or suspension, the vesselcan be sealed and an appropriate vacuum or pressure applied.

[0102] Application of the vacuum or pressure results in air that istrapped in the applicator tips being degassed, or forced out of theapplicator tips, and being replaced by the solution or suspension. Thisreplacement of air by the solution or suspension thereby loads thematerial onto or into the applicator tips. The end of the degassingphase can be observed by the absence of newly formed air bubbles. Aftera desired treatment time, the vacuum or pressure in the vessel can bereleased, and the treated applicator tips can be removed.

[0103] In exemplary embodiments, preparing an applicator for dispensingpolymerizable monomeric compositions includes applying a material to asuitable applicator tip, such as a porous polyethylene, foam or fibroustip, which is attached to an applicator body, such as a butyrateapplicator tube or other suitable holder.

[0104] When the applicator is intended to contain an amount ofpolymerizable monomeric composition, the applicator body or tube maycomprise a conduit or reservoir for the polymerizable monomericcomposition. In this embodiment, the applicator tip may be operablyconnected to the conduit or reservoir, such as by being fitted on anopen end of the conduit, so that fluid flowing through the conduit alsoflows through the applicator tip.

[0105] In addition to the polymerization and/or cross-linking initiatorand/or rate modifier, the applicator tip can also include various othermaterials that may or may not act as a polymerization initiator and/orrate modifier. For example, the applicator tip can include a flavorant,such that it imparts a flavor to the adhesive material when the adhesivematerial is applied to a surface. Incorporation of a flavorant isparticularly preferred, for example, when the cyanoacrylate adhesivematerial is to be applied to oral surfaces, such as to treat ulcers suchas stomatitis or cold sores. Similarly, the applicator tip can include abioactive material, which may or may not also be a polymerization and/orcross-linking initiator and/or rate modifier. Examples of suitablebioactive materials include, but are not limited to, medicaments such asantibiotics, antimicrobials, antiseptics, bacteriocins, bacteriostats,disinfectants, steroids, anesthetics, antifungal agents,anti-inflammatory agents, antibacterial agents, antiviral agents,antitumor agents, growth promoting substances, antioxidants, or mixturesthereof.

[0106] The applicator tip may be composed of any of a variety ofmaterials including polymerized materials such as plastics, foams,rubber, thermoset resins, films, fibers, or membranes. Where foams areused in the applicator tip, the foam can be either an open-celled form,a closed-cell foam, or a mixture thereof. Any suitable foam material canbe used and suitable foams include, for example, thermoplasticpolyurethane foam, preferably a soft, absorbent thermoplasticpolyurethane foam.

[0107] In embodiments, the applicator tip may be made from polyurethane,polyesters, polyolefins such as polyethylene, or polyamides. Inembodiments, the applicator may be made from polyethylene, such as thatsold by Porex Technologies Corp. (Fairbum, Ga.) under the trademarkLabPor®. In embodiments, the applicator tip can also be made fromfibers, either natural or synthetic, such as cotton, rayons, nylons, andmixtures thereof. Additionally, the applicator tip may be composed ofmaterials such as metal, glass, paper, ceramics, and the like. Theapplicator tip material may be porous, absorbent, or adsorbent in natureto enhance and facilitate loading of a material on or in the applicatortip. For example, the porous applicator tip may be composed of amaterial having random pores, capillaries, a honeycomb material, amaterial having a woven pattern, etc. The degree of porosity will dependon the materials being used, and can be determined by one of ordinaryskill in the art without undue experimentation. Porosity is the openvolume within the pores of an applicator tip divided by the total volumeof the applicator tip.

[0108] In embodiments, the applicator tip may be porous and have anaverage pore size of about 1 μm to about 500 μm. Generally, according tothe present invention, an applicator tip having an average pore size ofabout 1-100 μm such as 10-30 is used with a polymerizable materialhaving a viscosity of about 1-30 cP, preferably about 2-18 cP, and morepreferably 5-7 cP at 25° C. An applicator tip having an average poresize of from about 1 μm to about 100 μm is preferably used with apolymerizable material having a viscosity of about 10-30 cP. When thepolymerizable and/or crosslinkable material has a viscosity higher than7 cP, the average pore size of the applicator tip is generallyincreased. For example, an applicator tip having an average pore size ofabout 40-300 μm such as 60-125 μm is preferably used with apolymerizable material having a viscosity of about 30-500 cP, preferablyabout 35-350 cP, and more preferably about 50-200 or 60-140 cP at 25° C.In embodiments, an applicator tip has a pore volume of less than orequal to 80 percent, preferably between 20-60 percent.

[0109] In embodiments of the present invention, the adhesive compositionhas a viscosity of about 1-5000 centipoise, preferably 1-600 centipoise,more preferably 1-100 or 2-50 centipoise such as 2-18, 2-10 or 5-7centipoise, or 30-500 such as 50-100 or 100-200 centipoise at 25° C. Theviscosity can be selected according to the proposed use—e.g., 1-100centipoise for certain uses and 100-200 centipoise for other uses.Additionally, the composition may be a gel, e.g., 50,000-500,000centipoise at 25° C. Such gels are particularly advantageous inembodiments of the present invention, because the gels are more easilyexpelled through the applicator due to the decreased resistance totravel through the applicator tip provided by the present invention. Theviscosity of the adhesive composition can be measured with a BrookfieldViscometer. Additionally, in embodiments where a sterilization treatmentis applied, the viscosity of the composition should preferably bemaintained or increased by a controlled and acceptable amount aftersterilization.

[0110] The applicator tip according to the present invention, where itconnects to the applicator tube, may have an elongated tubular portion,out of which the mixed polymerizing and/or cross-linking material isexpelled. A portion of the applicator tip that is immediately downstreamof the applicator tube is advantageously porous in order to avoid asharp pressure drop and ensure a constant mixed ratio profile. Thestructure can preferably trap fragments of any barriers or materialsused to separate one or more components within the applicator containerso that they will not clog the device or contact the patient or surfaceonto which the adhesive is being applied.

[0111] When using a porous applicator tip to apply the adhesivecomposition, the composition preferably is not expressed directlythrough the applicator tip in a continuous motion. According toembodiments of the present invention, the adhesive composition is (1)expressed to the end or part way to the end of the applicator tip, (2)the pressure is released to draw the composition back into theapplicator, and (3) the composition is then subsequently expressedthrough the applicator tip in a continuous motion. This is called asuck-back method of applying the adhesive composition of the presentinvention. When used with a tip that bears an initiator, this methodlets the adhesive composition polymerize better than if it had beenexpressed directly through the tip.

[0112] According to the present invention, the applicator can bemanufactured in any of various ways, generally known in the art. Forexample, an applicator tube can be sealed at one end, and a frangiblevial containing the monomeric adhesive material can be placed in theapplicator tube. The remaining open end of the applicator tube can thenbe sealed by filling it with the applicator tip, which can be bonded orform-fit into the opening in the applicator tube. Such applicator tipcan be previously prepared to incorporate the polymerization initiatoror rate modifier, or the polymerization initiator or rate modifier canbe applied to the applicator tip subsequent to placing the applicatortip on the applicator. Furthermore, if desired, a second applicator tip,of the same or different design or configuration as the first applicatortip, can be affixed at the opposite end of the applicator tube ratherthan sealing the applicator tube. Such second applicator tip can havethe same of different constructions as those described above.

[0113] However, the present invention further provides an alternativemeans for forming the applicator assembly. According to embodiments ofthe present invention, the applicator tip can be first applied to anopen end of the applicator body, and the polymerization initiator orrate modifier can be applied to the applicator tip through the length ofthe applicator body. Once the initiator is applied, the frangible vialcan be inserted into the applicator body, and then the remaining openend of the applicator body can be sealed.

[0114] According to this embodiment of the present invention, theapplicator tip is first applied to an open end of the applicator body.The applicator tip can be applied to the applicator body by any suitablemethod, as described above. Next, the polymerization initiator or ratemodifier is applied to the applicator tip. The polymerization initiatoror rate modifier can be applied, for example, by dispensing the materialonto the back (inside or proximal) end of the applicator tip, forexample, by using a standard dispensing nozzle or injection syringe.

[0115] Once the polymerization initiator or rate modifier has beenapplied to the applicator tip, the frangible vial containing themonomeric adhesive material can be inserted into the applicator tube. Inthis manner, the frangible vial can rest up against the back end of theapplicator tip.

[0116] Next, the remaining open end of the applicator body is sealed.The sealing can be affected by any suitable means known in the art. Forexample, the applicator tube can be sealed by heat, the open end can becovered, for example by a cap, or the like. Where a separate cap is usedto seal the applicator body, it is preferred that the cap is bonded tothe applicator body, for example by ultrasonic welding, chemicalbonding, physical bonding (such as adhesive), or the like.

[0117] Once the applicator assembly is prepared, the assembly (orindividual components thereof) can be sterilized according to knownpractices. Compatibility of the adhesive composition and the applicatorwith one or more sterilization procedures is preferred in embodiments ofthe present invention because many uses of the adhesive compositions,such as many surgical and other medical applications, require sterilizedproducts. In preferred embodiments, there is substantially no initiationof polymerization of monomeric liquid adhesive compositions that affectsthe utility of the monomer or monomers caused by the sterilizationprocess.

[0118] Sterilization of the monomer composition and/or its packaging canbe accomplished by techniques known to the skilled artisan, and ispreferably accomplished by methods including, but not limited to,chemical, physical, and/or irradiation methods. Examples of chemicalmethods include, but are not limited to, exposure to ethylene oxide orhydrogen peroxide vapor. Examples of physical methods include, but arenot limited to, sterilization by heat (dry or moist) or retort canning.Examples of irradiation methods include, but are not limited to, gammairradiation, electron beam irradiation, and microwave irradiation. Apreferred method is electron beam irradiation. In embodiments where acomposition is to be used for medical applications, the sterilizedcomposition must show low levels of toxicity to living tissue during itsuseful life.

[0119] While the invention has been described with reference topreferred embodiments, the invention is not limited to the specificexamples given, and other embodiments and modifications can be made bythose skilled in the art without departing from the spirit and scope ofthe invention.

What is claimed is:
 1. A method of preparing an applicator tip suitablefor dispensing a synthetic or semi-synthetic polymerizable orcross-linkable monomer material, comprising providing an applicator tiphaving a proximal end and a distal end, forming one or more cuts in saidapplicator tip to alter flow properties of said adhesive materialthrough said applicator tip, wherein said applicator tip is a non-porousapplicator tip.
 2. The method of claim 1, wherein said one or more cutsis formed as one or more channels through said applicator tip.
 3. Themethod of claim 2, wherein said applicator tip has a polymerization orcross-linking initiator or rate modifier for said adhesive materialdisposed on exposed surfaces of said channels.
 4. An article ofmanufacture for dispensing adhesive material, comprising: a containerbody and an applicator tip, and an adhesive material located in saidcontainer body in a non-contacting relationship with said applicator tipprior to dispensing said adhesive material, wherein said applicator tiphas a proximal end that is attached to said container body and a distalend located away from said container body, and wherein said applicatortip comprises one or more porous sections and one or more non-poroussections, wherein said adhesive material flows substantially onlythrough said one or more porous sections.
 5. The article of claim 4,wherein the one or more porous sections extends from said proximal endto said distal end.
 6. The article of claim 4, wherein the one or morenon-porous sections extends from said proximal end to said distal end.7. The article of claim 4, wherein a total exposed surface area of saidone or more porous sections at said proximal end is greater than a totalexposed surface area of said one or more porous sections at said distalend.
 8. The article of claim 4, wherein the applicator tip consists ofone porous section located symmetrically within the one or morenon-porous sections.
 9. The article of claim 4, wherein the applicatortip consists of one porous section located asymmetrically within the oneor more non-porous sections.
 10. The article of claim 4, wherein saidone or more porous sections has a polymerization or cross-linkinginitiator or rate modifier for said adhesive material disposed thereonor therein.
 11. The article of claim 4, wherein said applicator tip ishollow.
 12. The article of claim 4, wherein said adhesive material is asynthetic polymerizable or cross-linkable monomer material.
 13. Thearticle of claim 4, wherein said adhesive material comprises1,1-disubstituted ethylene monomers.
 14. The article of claim 4, whereinsaid adhesive material comprises α-cyanoacrylate monomers.
 15. Thearticle of claim 4, wherein a shape of said applicator tip is selectedfrom the group consisting of dome, conical, cylindrical, chisel andpolygonal shapes.
 16. The article of claim 4, wherein said proximal endof said applicator tip is curved.
 17. The article of claim 4, whereinsaid applicator tip is in a shape of a hollow dome.
 18. The article ofclaim 4, wherein the applicator tip is attached to the container body bya luer lock.
 19. The article of claim 4, wherein said applicator tip isin a shape of a chisel.
 20. The article of claim 4, wherein saidadhesive material has a viscosity of 1-30 cP at 25° C.
 21. The articleof claim 4, wherein said adhesive material has a viscosity of 2-18 cP at25° C.